At present, a wide variety of animal and plant cells are cultured, and novel cell culture techniques are being developed. Cell culture techniques are conducted for the purpose of elucidation of biochemical phenomena and cell properties, production of useful substances, and other purposes. In addition, inspection of physiological activity or toxicity of artificially synthesized drugs has been attempted with the use of cultured cells.
Some cells (many animal cells, in particular) have adhesion-dependent properties, such that they grow while adhering to other substances. Thus, such cells cannot survive for a long period of time if they are in suspension outside an organism. Culture of such adhesion dependent cells necessitates the use of a support to which cells adhere, and a plastic culture dish that is evenly coated with a cell-adhesive protein, such as collagen or fibronectin, is generally used. Such cell-adhesive protein is known to act on cultured cells, facilitate cell adhesion, and influence cellular configurations.
In order to evaluate functions of cells that survive while adhering to other substances in vivo, accordingly, it is necessary that cells be cultured while adhering to other substances. When cell-to-cell interactions are to be evaluated, it is also preferable that adhered cells be subjected to co-culture and interactions be evaluated. Even though it has been possible for cells to adhere to specific regions that have been selectively made cell-adhesive on a support, it has been difficult to cause two or more types of cells separately adhere to different regions. Accordingly, development of techniques that enable modification of cell adhesiveness under given conditions and regulation of regions to which cells are allowed to adhere or are not allowed to adhere, depending on cell type, has been awaited.
Non-Patent Document 1 describes that cells that had adhered to specific regions on a substrate that is not patterned and is conductive across its entire surface are released and diffused from such regions upon application of potentials. However, Non-Patent Document 1 does not describe that a conductive region is converted into a cell-adhesive region upon application of potentials. In addition, Non-Patent Document 1 does not describe regulation of regions to which cells are allowed to adhere.
Non-Patent Document 2 describes a method of cell culture comprising forming a non-cell-adhesive membrane on a base material upon which a conductive region and an insulating region are provided, applying an electric potential to a given conductive region to modify the non-cell-adhesive membrane into a cell-adhesive membrane, and allowing cells to adhere selectively to such region.